4 beginner Docker mistakes I made that took my homelab offline — and how I fixed each one

Source Domain: www.makeuseof.com

Breaking my own server came with a sinking feeling as I saw my network suddenly drop, and my dashboard go dark. I self-host using Docker, and it’s been incredibly easy. However, with the slightest oversight, you can accidentally weaponize a container against your hardware. I learned the hard way when I choked my device with unconstrained memory limits and rogue logs.

This is just one of the many Docker mistakes I’ve made over the years. Here are the ones I regret the most and how I fixed them.

I ignored memory limits

One container ate everything

Afam Onyimadu / MUO

I’m used to having operating systems manage memory use. For instance, when I open several browser tabs, the browser freezes idle background tabs to free up RAM. I assumed that’s how Docker worked, but I was wrong.

It was one afternoon, after my server ground to a halt with timed-out SSH connections and an unresponsive dashboard, that I learned the lesson. I initially thought it was a failing hardware component, but it turned out to be a single container hogging too much memory.

By default, Docker doesn’t impose memory limits on containers. Without asking for permission, Linux’s OOM killer terminates processes to recover memory when the system runs out of RAM. Even important processes may be terminated.

The OOM killer prioritizes processes by a score it calculates automatically, which…

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